【codeforces 801A】Vicious Keyboard

【题目链接】:http://codeforces.com/contest/801/problem/A

【题意】

一个字符串只由VK组成;
让你修改一个字符;
使得剩下的字符串里面子串VK的个数最大;

【题解】

枚举修改哪一个字符;
然后获取剩余的字符里面VK的数的个数;
取MAX就好;

【Number Of WA】

0

【完整代码】

#include 
using namespace std;
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define LL long long
#define rep1(i,a,b) for (int i = a;i <= b;i++)
#define rep2(i,a,b) for (int i = a;i >= b;i--)
#define mp make_pair
#define ps push_back
#define fi first
#define se second
#define rei(x) cin >> x
#define pri(x) cout << x
#define ms(x,y) memset(x,y,sizeof x)

typedef pair<int,int> pii;
typedef pair pll;

const int dx[9] = {0,1,-1,0,0,-1,-1,1,1};
const int dy[9] = {0,0,0,-1,1,-1,1,-1,1};
const double pi = acos(-1.0);
const int N = 110;

string s;
int ans;

int cnt(string ts)
{
    int now = 0;
    int len = ts.size();
    rep1(i,1,len-1)
    {
        if (s[i-1]=='V'&&s[i]=='K')
            now++;
    }
    return now;
}

int main()
{
    //freopen("F:\\rush.txt","r",stdin);
    ios::sync_with_stdio(false);
    cin >> s;
    int len = s.size();
    ans = cnt(s);
    rep1(i,0,len-1)
    {
        char t = s[i];
        if (t=='V')
            s[i]='K';
        else
            s[i]='V';
        ans = max(ans,cnt(s));
        s[i] = t;
    }
    cout << ans << endl;
    //printf("\n%.2lf sec \n", (double)clock() / CLOCKS_PER_SEC);
    return 0;
}

转载于:https://www.cnblogs.com/AWCXV/p/7626429.html